Venturi systems are generally used in a variety of industries to add or inject a gas or a liquid into an existing stream of liquid. Venturi systems are typically designed for a given motive flow and operate on a narrow range. For example, if a venturi system is designed for a motive flow of 10 gallons per minute (GPM), it may have an effective range between approximately 6 GPM and 14 GPM. Specifically, a motive flow below approximately 6 GPM may not initiate suction and a motive flow above approximately 14 GPM may create an excessively unacceptable pressure drop.
In situations where the motive flow may vary significantly, the venturi system may be implemented with a bypass module or system to address this. For example, if a given application has a flow rate of approximately 100 GPM and includes an injection of a gas or liquid, a user may choose a venturi system that is designed for an ideal motive flow of 10 GPM. In such a case, a bypass loop may be created to allow approximately 90 GPM to flow through the bypass module and approximately 10 GPM to flow through the venturi system.
A venturi bypass module or system may include two separate loops or paths, e.g., a venturi path and a bypass loop. In a situation which requires a total fluid flow of approximately 100 GPM, the venturi chosen may require 10 GPM, the bypass therefore being approximately 90 GPM to provide for the remaining fluid flow passing through the system.
A restriction in the bypass loop may be created in a variety of ways. Some bypass modules in the industry use either a manually adjusted bypass valve or an automatic bypass valve to achieve the proper motive flow through the venturi. For example, a manual valve incorporated into a bypass loop can be restricted to a point where the proper motive flow through the venturi can be achieved. As the overall fluid flow changes through the venturi system, the manual valve restriction can be provided with readjustment to maintain the ideal motive flow through the venturi. Automatic bypass valves may use a variety of methods to automatically restrict the bypass flow to such a degree that the ideal motive flow through the venturi can be maintained. For example, a spring-loaded valve can be used to create an automatic bypass valve. By choosing the proper spring tension, the bypass flow can be regulated to maintain the fluid flow through the venturi near or at the ideal motive flow.
In general, a traditional venturi bypass module or system can be created as a venturi-preference bypass module or a bypass-preference bypass module. With reference to FIG. 1, a diagram of a traditional venturi-preference bypass module 10 is provided. In the bypass module 10, fluid, such as water, can flow through a venturi 12 in a substantially straight line between a fluid inlet 14 and a fluid outlet 16 that is in-line with the fluid inlet 14. The venturi 12 can include a suction port 18 leading into the venturi 12. The bypass loop 20 can be defined by a number of turns, e.g., offset passages relative to the in-line (e.g., straight) passage between the fluid inlet 14 and the fluid outlet 16. For example, the bypass loop 20 can separate at a joint 24, e.g., a T-joint, from the total fluid flow entering through the fluid inlet 14. The bypass loop 20 can include a bypass valve 22 before the bypass loop 20 rejoins the total fluid flow at a joint 26, e.g., a T-joint, prior to the fluid outlet 16. The bypass valve 22 can be regulated to vary a restriction of fluid flow through the bypass loop 20.
The bypass module 10 configuration of FIG. 1 can provide a clean flow path for the venturi 12 with a high fluid inlet 14 pressure and a low fluid outlet 16 pressure to create a maximum suction into the venturi 12 through the suction port 18. In addition, the incoming fluid flowing through the venturi 12 in a straight line, in combination with the forced fluid turn into the bypass loop 20, can create a desirable “ram pressure” on the venturi 12 inlet. The bypass loop 20 may need a restriction therein such that, for example, approximately 10 GPM can flow through the venturi 12. For example, if the bypass loop 20 was a clean, straight piece of pipe, the fluid flowing through the bypass module 10 may take the path of least resistance, thereby not necessarily being focused through the venturi 12. By having the fluid flow through a number of T-joints and elbow fittings, e.g., joints 24, 26, in the bypass loop 20, a restriction of the bypass loop 20 can be created. The created restriction of the bypass loop 20 generally provides less of a pressure drop through the bypass valve 22 than the pressure drop of the bypass-preference bypass module 50 described below with respect to FIG. 2.
With reference to FIG. 2, a diagram of a traditional bypass-preference bypass module 50 is provided. In the bypass module 50, fluid can flow in-line through the bypass path 52, including a bypass valve 54, in a substantially straight line between a fluid inlet 56 and a fluid outlet 58. The fluid flow into and through a venturi 60 can take a number of turns before rejoining the total fluid flow. For example, the venturi 60 can separate at a joint 62, e.g., a T-joint, from the total fluid flow entering through the fluid inlet 56, pass through the venturi 60 and connect to the total fluid flow at a joint 64, e.g., a T-joint, before the fluid outlet 58. The venturi 60 can include a suction port 66 leading into the venturi 60.
The bypass module 50 configuration of FIG. 2 generally creates a cleaner flow path through the bypass path 52 than the venturi 60. However, this may defeat a purpose of the bypass path 52 (to create a restriction in the bypass module 50). A greater pressure drop through the bypass valve 54 can typically be used to compensate for the cleaner flow path through the bypass path 52.
The bypass module 10 configuration of FIG. 1. may be considered to be more efficient than the bypass module 50 configuration of FIG. 2 due to a smaller pressure drop and a greater suction at the venturi 12. However, both bypass modules 10 and 50 still incur high pressure drops at points where fluid flowing from the venturi 12 and 60 mixes with fluid discharged from the bypass loop 20 in a turbulent manner due to the perpendicular orientation of the fluids. This high pressure drop can require additional pump horsepower to maintain the desired fluid flow through the venturi 12 and 60. The additional pump horsepower can translate into additional or higher energy usage for the bypass modules 10 and 50.
Thus, a need exists for a venturi bypass system which provides greater efficiency, including a reduced pressure drop between an inlet and an outlet to achieve a required suction and/or an improved suction without increasing a pressure drop. These and other needs are addressed by the venturi bypass systems and associated methods of the present disclosure.